At Any Time; There is Only One Theory.

One of the more common yet forgivable errors a physicist can make is to try to come up with a new theory that fully explains and links together all aspects of the universe. To truly have a solid understanding of physics is to realize that, at any time, there is only one theory. So by all means let us bring on the hypotheses all we want but let us also not forget that theory is always one which is why it is called a (meaning one) theory of everything to begin with.
~ Wald Wassermann, Physicist